The generation of a Gaussian random process in a position parameter

Analog computer method for approximating stationary Gaussian random process depending only on position paramete

Three-Bladed Propeller Design for the Reduction of General Aviation Radiated Noise Characteristics

The purpose of this study was to design a quiet 3-Bladed propeller for general aviation aircraft. A combination of design technique and analytical predictions using the NASA Aircraft Noise Prediction Program - Propeller Analysis System (ANOPP-PAS) was used to achieve this goal. The propellers were designed for an engine power of 200 hp, a rotational speed of 2,400 RPM and a free-stream speed of 160 kts. A straight 76 in. diameter 2-bladed propeller was designed as a reference for the 64 in. diameter 3-bladed propeller. The ANOPP-PAS computer code was used for predicting the aerodynamic performance and radiated noise characteristics for both the 2-bladed and 3-bladed propeller designs. Through blade design modifications and the use of conventional, as well as specifically designed natural-laminar-flow (NLF) airfoils, 3-bladed propeller designs resulted in predicted noise reductions of 3.4 dB in the near-field which corresponds to 5.1 dBA; and a 3.4 dB (7.0 dBA) in the far-field when compared to the 2-bladed propeller. These 3-bladed designs resulted in no appreciable change in aerodynamic performance but an estimated 43% weight increase

Armor

I never played sports. It never felt right or good. Sports created a space in which my body would be on display. A display which invited attention to a performance of masculinity. And under that scrutiny, I would fail. Fail to perform with the strength I was expected to exhibit. Removed from the pressure of performance, I can consider the equipment, the gear, the spaces and re-materialize them. I shift what is on display. Displaying the altered objects rather than the body and its performance. Looking at the objects not as tools for the body to interact with but as pieces that perform on their own. Game and combat. Play and fight. In my own private game I wrestle with myself. Playing internal defense and offense, back and forth of doubt. The mind plays tricks, the tricks play me

A program to evaluate a control system based on feedback of aerodynamic pressure differentials, part 1

The use of pressure differentials in a flight control system was evaluated. The pressure profile around the test surface was determined using two techniques: (1) windtunnel data (actual); and (2) NASA/Langley Single Element Airfoil Computer Program (theoretical). The system designed to evaluate the concept of using pressure differentials is composed of a sensor drive and power amplifiers, actuator, position potentiometer, and a control surface. The characteristics (both desired and actual) of the system and each individual component were analyzed. The desired characteristics of the system as a whole are given. The flight control system developed, the testing procedures and data reduction methods used, and theoretical frequency response analysis are described

Estimating Post-Liquefaction Displacements in Embankment Dams and Priorities Remediation Measures

Large displacement analysis is used to simulate the failures of flood protection dikes in Hokkaido, Japan, which occurred during the 1993 Kushiro-oki earthquake. These studies served to validate the method of analysis. The analysis was then used to predict displacements in dikes with potential for liquefaction by relating displacements to geometric characteristics of the dikes: height, slopes, and thickness of potentially liquefiable layer. The predictions were verified using dike displacement data from the Nansei-oki earthquake of 1994. The basis for reliable post-liquefaction analysis is a good estimate of the residual strength of the liquefied soils. For this reason, recent developments in evaluating residual strength are reviewed